The number of subway passengers has grown quickly this year, prompting the operator to ask non-commuters to avoid taking metro trains during rush hours.

The two subway lines and the elevated metro line carried an average of 1.51 million passengers per day this year, soaring 23.5 percent from a year earlier, according to Shanghai Metro Operation Co Ltd, the operator of the three lines.

Growth since the beginning of March hit 31.43 percent, rising to 1.72 million per day, compared with the year-on-year rise of 16 percent in 2004.

The main reason for the growth in passengers is the northern extension of RT No. 1 that opened in December, Shanghai metro officials said.

"The passenger flow increase is due to a number of factors, but the extension of the northern line is the biggest reason," said Zou Song, a public relations official with the firm.

Trains on the 12.43-kilometer-long northern extension of RT No. 1, which extends from Shanghai Railway Station to Gongfu Xin Cun Station in Baoshan District, are always at full capacity as it operates at an interval of 12 minutes.

More commuters are taking the subway to work as well. "Some people used to regard it as more costly to take subway trains than buses. But now they want to take underground railways as street traffic is terrible," said Shao Weizhong, vice-general manager of the company.

The operator also faces a shortage of trains.

Zhu Xiaojie, who is in charge of operation security, said: "We are waiting for more trains, but it takes a long time for one to be built as they are tailor made." Eventually, intervals will be reduced to 2.5 minutes during peak hours, but that will not happen until 2007.

The company estimated that 20 percent of subway passengers are non-commuters - those who do not need to get to work or school - and has called for these individuals to avoid taking trains between 7:30am and 8:30am.

"It doesn't mean they can't take the subway," Vice General Manager Shao said. "But the overcrowding is dangerous. If they could just wait until non-peak hours, the situation would be better."

(Shanghai Daily March 18, 2005)